1. Field of the Invention
The present invention relates to cables and conductors and, in particular, to insulation therefore.
2. Brief Description of the Prior Art
In alternating current or direct current electrical power transmission, electrical conduction processes in condensed matter, under certain conditions, consist of the transport of heat, electric charge, mass, and magnetism or some combination of the four in some possible response to an imposed temperature gradient, electric field, density gradient, or magnetic field.
Electrical conductivities vary greatly between various materials, and conductivities may vary by an amount of 20 decades or more between metals and most commercially used insulating materials. In electrical cables a thermodynamic equilibrium is established between the particular materials used as the electrical insulation and the electrical conductors.
Influences on the conduction processes in insulation are known as traps, polarizability or treeing. Such influences contribute to what is known as electrical breakdown, either thermal or electronic. External cold temperature plays a part in insulation degradation (i.e., cracking) by what is known as cold bend or static temperature. An insulation or dielectric material can under certain conditions experience dielectric breakdown or may spark over when the insulation or dielectric strength drops either because of deterioration, impurities, moisture or physical abuse or damage by the user or abnormal electrical conditions. The existence of foreign materials in the insulation and also what is known as electrically stressed insulation, may under certain conditions result in dielectric break down resulting in heating and unwanted shorts. Some dielectric heating may also result from molecular friction from alternating current which may result in a dielectric loss and dielectric strength drops. Presently today""s commercial insulation on an electrical cable assembly or wire hides electrical damage and does not have the capabilities to indicate and/or locate varied inner cable faults and/or malfunctions and/or damage and/or hazards.
Therefore, it is an object of the present invention to provide an electrical cable assembly that will indicate, through an attention getting means, preferable visually through sight or smell or taste or touch, the presence of a fault and/or malfunction and/or damage and/or hazard in the electrical cable assembly. A further object of the present invention relates to a repair jacket and tape to be used in combination with an electrical cable assembly where in the repair jacket or tape also has the capability to indicate the presence of electrical repaired cable faults, and/or malfunction, and/or damage, and/or hazard by an attention getting means.
It is an object of this invention to provide a new jacket, sheath or insulation covering for electrical cables or a new electrical cable assembly with at least one attention getting stimulation means, which will be know as a reactee, having a noticeable awareness means, by giving off at least one response by a reacting material that may be at least one visual or color change that is temporary or permanent or in combination and/or testable and/or odoriferous and/or physically changeable that may extend or travel through some dimension of the cable that will:
detect an electrical overload condition of itself;
detect and/or locate the spot of internal electric sparks and arcs and/or a pre-shortening condition, and/or an intermittent malfunction;
detect and/or locate the spot where the beginning of an internal dielectric break down process is starting and/or taking place;
detect and/or locate the spot where internal dielectric break down is occurring and/or was occurring;
give information as to whether a particular circuit is on or off under the proper environmental and engineered conditions;
give an indication of an arc or spark and or dielectric break down and the conduction process occurring internally;
detect and/or locate its own internal electrical malfunction quickly without devices or electrical and electronic instruments, making itself capable of indicating its own condition or conditional level without reference to a normal function, and may automatically reset itself with no calibration needed;
allow inspectors to see dangerous cable and wires that should be taken out of service;
reduce the risk of fires, electrical shock and electrocution and thus make for a safer electrical distribution system;
warns of harsh environment temperature, example: cold bend, xe2x80x9cWARNINGxe2x80x94DO NOT BEND,xe2x80x9d so cable insulation does not crack when cable assembly is bent;
give a visual warning of the existence of critical temperature ranges or thermal ratings for electrical insulation as is set forth by the National Electric Code or a governing agency or a manufacturer""s specifications:
to deter a child or pet from playing with (i.e., especially putting in the mouth);
provide any of the above mentioned functions so that a partially color blind persons can see critical points or critical temperatures and detect and/or locate electrical problems;
provide any of the above mentioned functions so a totally blind person can tell a critical point or critical temperature and detect and/or locate electrical problems;
provide any of the above mentioned functions so that the hearing impaired person can identify a critical point or critical temperature and detect and/or locate electrical problems;
provide any of the above mentioned functions if desired a better higher surface electrical resistance of ohmic values by spacing strategically the visually reacting formulation so a surface area of higher resistance surrounds the surface area of a lower resistance visually reacting formulation or by adding at least one additive;
provide any of the above mentioned functions with a displayable form of moving colors, or a color moving effect, and/or a readable language or alphanumerics.
This new electrical cable assembly, repair jacket and tape, alone or in combination, consist of an electrically insulating means which can be described as containing or coupled to a reacting material. The reacting material, a reactee, reacts while maintaining its insulating properties to various cable conditions. The reacting material can be coupled to an electrically extending electrovisual wire, cord or cable. A reactor is an internal and/or outer abnormal condition occurring within or on an electrical cable assembly and having noticeable results to the outside of the electrical cable assembly through the reacting material, the reactee. The preferred action of the electrically insulating means is an outer visually reacting reactee reacting to an internal reactor.
The term xe2x80x9creactivexe2x80x9d or xe2x80x9creactingxe2x80x9d as used herein will be understood to mean a change which will gain the attention on one via the sense of sight or touch. Examples include color changes or lettering or words which suddenly appear and become visible or physical deformations like swelling, blistering, shrinking and/or melting. Other sensory-like changes will include non-palatability when a material or composition is chewed or bitten into, (i.e., hot pepper extract, citric acid, etc.) or audio resulting from special materials that produce sounds when undergoing physical deformation, and/or smell, from releasing material composition (i.e., methyl nonylketone, oil base odor releasing gels, a sulfur base composition that may contain chlorides, etc.).
The term xe2x80x9celectrical cablexe2x80x9d as used herein will be understood to mean or comprise an electrical wire, cable or cord, electrically insulated wire conductor, an electrical cable assembly or anything used in the form of an extending or rope-like insulating and conducting medium for the transmission, distribution, conduction or retainment of electrical energy. The electrical cable may have at least one delivery system, for example, an insulated conducting path, which is used as a facilitator for the transmission, distribution, conduction or retainment of electrical energy. The electrical cable assemblies disclosed in this patent application may facilitate electrical energy of the alternating current, direct current, analog, or digital type. The electrical cable assemblies discussed in the patent application may also use the inventive features in this patent application separately or in some combination. The term xe2x80x9cvisually reactive materialxe2x80x9d or xe2x80x9cvisually reacting materialxe2x80x9d as used herein may be, but is not limited to, a liquid crystal material because of (i.e., electrorheological fluid, magnetorheological fluid, thermochromic polymer gels). Preferred liquid crystals derive from the thermotropic group, particularly: cholesteric and/or chiral nematic subgroups. They may have designer formulations so that they function via color change within a predetermined range. The term xe2x80x9cvisually reactive materialxe2x80x9d or xe2x80x9cvisually reacting materialxe2x80x9d may also include electrical or magnetic field sensitive compounds that can also display a color change due to variations in electrical or magnetic field sensitive compounds that can also display a color change due to variations in electrical or magnetic fields. Additionally, some chemical compounds exist in materials that produce deformations in themselves and the surfaces to which they are coupled when subjected to pressure variations (i.e., pressure variations stemming from variations in heat within an electrical cable assembly).
The term xe2x80x9cvisually reacting materialxe2x80x9d as used herein may be a thermochromic liquid crystal material which may be selected from but not limited to one or more of the following: Methoxybenzylidenebutylaniline or terephthal-bis-p-butylanaline. Some preferred liquid crystal materials are commercially available from the company xe2x80x9cHallcrestxe2x80x9d under trade names BN-g90 C5w, BCN-g100 C, BCN-g-30 C5w, BN-R88 F10w, BN-G98 FLOW or BN-R98 FLOW. xe2x80x9cVisually reacting materialsxe2x80x9d of the type that visually indicate variations in electrical or magnetic fields may be commercially available from the company xe2x80x9cE.M. Science Co.xe2x80x9d under the trade name of Licrilite.
The term xe2x80x9cvisually reacting materialxe2x80x9d will also include thermochromic ink and/or die and/or paint compositions and/or a thermochromic polymer and/or a liquid crystal polymer. It is found that some visually reacting materials may be advantageously used in amounts from 0.05 to 5 grams per square foot. Attention getting materials or visual reactance may be in powered form.
The term xe2x80x9cvisually reacting materialxe2x80x9d will also include any other material that emits light or has a fluorescence property or changes in transparent, or in color in response to, changes in temperature or electrical activity. These materials may also exist in the form of slurries, inks, dyes, paint combinations or can be impressed/impregnated in any flexible or inflexible substance so that the material can be coupled in some manner to an electrical cable assembly, repair jacket and/or tape.
Some visually reacting materials may require a specific background or dropback of a certain color in order to properly contract the visually reacting material when it undergoes a color change. This background can be used to enhance, aid or manipulate the visual effect of the visually reacting material. The color of the background can be made from inks, paints, dyes or even the natural color of the cable or its insulation or the color stemming from their ordinary manufacturing processes.
Protective coverings, which may range from transparent to opaque, may be utilized to protect some types of visual reacting materials or reactees. The protective coverings may also have an electromagnetic frequency selectivity ability. They may also have some of the proprieties of filtering, absorbing or reflecting lightwaves so as to transform the reactions of the reactor or reactee in order to aid the reacting material""s reactance to it. Protective coverings may also be designed for harsh environments or weatherproofing. This new electrical cable assembly, repair jacket and tape, alone or in combination, may also consist of this protective cover which can be described as containing or coupled to a reacting material, to be known as a reactee reacting to a reactor, while maintaining its protective properties.
The term xe2x80x9cprotectivexe2x80x9d will be understood to mean protection for visually reactive material from environmental harm. Some examples are the damaging effects of chemicals, solvents, oils, moisture, water, radiation, sun rays, insects and animals or weather conditions. Further, the electrical insulation of an electrical cable assembly, repair jacket or tape may contain insect, animal and/or child-protective or repulsive qualities (i.e., an unpalatable insulation composition, i.e. methyl nonylketone, hot pepper extract, citric acid, etc.).
Even a protective cover may have visually reacting results or physical deformations by way of polymer liquid crystals or thermochromic impregnated rubber compound coatings or heat-shrinking polyester coatings that blister, bubble or peel on a cable subjected to a malfunction which causes a variation in the cable""s temperature or electrical/magnetic field. The protective cover may also be heat retaining or heat reflective or heat conducting depending on desired results that my be wanted from such protective coverings.
The term xe2x80x9ctransparent,xe2x80x9d as used herein as a property of a protective covering will be understood to mean clear, color-tinted or semitransparent or as understood in the art. The transparent protective covering may have openings used as vents and/or transparent protective coverings may be made of a porous material (i.e., osmotic polymer or a semi-permeable membrane).
Another feature of the present invention is that the electric cable assembly may contain a bad tasting composition to prevent the cable from being chewed by rodents or other animals, which may act as a pet or child-proofing. In another extreme it may be designed to attract insects and rodents in order to trap or exterminate them.
The term xe2x80x9ccouplexe2x80x9d will be understood to mean containing, or united with, any manufacturing process that makes (i.e., screening, layer, impregnate, film, paint, die, etc.) in order to join together various materials, structures, or layers of an electrical cable assembly, that has means for indicating all functions therein, in particularly the means.
The next three terms xe2x80x9cdamagexe2x80x9d, xe2x80x9cfaultxe2x80x9d, and xe2x80x9chazardxe2x80x9d are mentioned together here not only because of their differences but because of their relative relationships with one another. The three terms xe2x80x9cdamagexe2x80x9d, xe2x80x9cfaultxe2x80x9d, and xe2x80x9chazardxe2x80x9d as used herein will be understood to mean the following as described in the next three paragraphs.
The term xe2x80x9cdamagexe2x80x9d as used herein will be understood to mean: any physical injury or harm suffered by an electrical cable assembly. This may include any abnormal material condition occurring, or that has occurred, or that may occur in, and/or on an electrical cable assembly, either to an insulation thereof (i.e., traps, polorizability, treeing, dielectric breakdown, thermo breakdown, etc.) and/or a conductor within the electric cable assembly (i.e., an open conductor, an intermittent conduction by conductor, an irregularity etc.).
The term xe2x80x9cfaultxe2x80x9d as used herein will be understood to mean: any electrical conduction process, and/or electrical condition that is abnormal for an electrical cable assembly (i.e., shorts, ground, phase to phase, return to hot, overload, under voltage load resistance short, etc.).
The term xe2x80x9chazardxe2x80x9d as used herein will be understood to mean: a risk of danger, because of an increment of deterioration to be and/or done, either by damage and/or fault to an electrical cable assembly. Thus a hazardous electrical cable assembly may have at least one damage resulting in at least one fault, and/or at least one fault resulting in at least one damage to an electrical cable assembly. Both damage and fault may, under certain conditions, give variation in temperature, and/or agenetic, and/or electrical fields. When the two results, fault nd damage feed one another, a serious situation develops that can get very dangerous, fires or electrocution and the likes will result especially when fuses or breakers do not work properly for whatever reason. Thus making my electrical insulated cable having means or manifestation abilities for indicating malfunction therein, an excellent warning means, detecting trouble, potential trouble, and/or location of, in and/or on an electrical cable assembly, by this new electrical cable assembly itself.
Therefore, I have invented a hazard and/or fault self-indicating electrical cable assembly, repair jacket and tape which may be used in conjunction with one another or alone. The electrical cable assembly may include electrical insulation surrounding electrical wires, wherein the insulation is covered by a layer of or impregnated with a reacting and/or visually reacting material. The layer of reacting material and/or the layer of visually reacting material or impregnated insulation may then be covered by a transparent protective cover and/or may be a protective cover with a means to path the release of responses of reactable materials, and protective cover may be reactive. In another embodiment, the electrical cable assembly and repair jacket may also have visually reacting material embedded in a groove that runs axially to the electrical cable assembly. Furthermore, the reacting and/or visually reacting material may be arranged on the outside of the electrical insulation in spaced repeating sets of locations and/or markings where a set is comprised of multiple locations and/or makings of reacting and/or visually reacting material. Each mark and/or location within a set would be capable of measuring a different magnitude of a hazard an/or fault and/or producing a different response to same magnitude of hazard and/or fault. Alternatively, each spaced repeating sets of markings can be spaced repeating sets of bands that encircle the cable assembly and give the appearance of motion. These locations and/or marks or bands may also be embedded into the transparent protective layer rather than layered atop the insulation. Reacting and/or visually reacting material may also be applied to the outer surface of the insulation in the form of descriptive words or alphanumerics so that these would communicate a hazard and/or fault to a user or observer in a special predetermined manner.
An embodiment of the hazard and/or fault self-indicating electrical cable repair jacket comprises a shell formed as a rectangular or tubular sleeve member where the shell is composed of an electrical insulation covered by a reacting and/or visually reacting material. The jacket may have a longitudinal split on one side to facilitate adapting it over and around an electrical cable, possibly for cable repair purposes, or electrical trouble shooting. Reacting and/or visually reacting material may be either layered on the outside or impregnated into the insulation and may be covered by a transparent protective cover like that of the cable assembly. In another embodiment, the electrical cable jacket may be a tubular sleeve-like member where the inner diameter of the jacket is larger than the outer diameter of an electrical cable so that a small gap is formed, possibly for fire-preventative purposes whereby the jacket acts as a flame conduit.
An embodiment of the fault-indicating electrical tape comprises a substrate with an adhesive backing on one side and on the opposed side a reacting and/or visually reacting material which may be covered by a transparent protective cover like that of the cable assembly. Alternatively, the electrical tape may include electrical insulation on the opposed side whereby visually reacting material may be embedded into this insulation. This tape will be flexible, and may be stretchable.
The electrical cable of the present invention is further described with reference to the attached drawings in which:
FIGS. 1a, 1b, and 1c are respectively longitudinal, transverse and longitudinal cross sections views of an electrical cable which is a preferred embodiment of the present invention;
FIG. 2 is a cross-sectional view of an electrical cable embodying an alternate form of the present invention and including a detectable irregularity and/or an impurity;
FIG. 3 is a cross-sectional view of an electrical cable embodying still another form of the present invention and in which several detectable malfunctions are also illustrated;
FIG. 4 is a schematic illustration of various aspects of the operation of the cable shown in FIG. 3;
FIG. 5 is a top perspective view of a cable jacket embodying still another form of the present invention;
FIG. 6 is a bottom perspective view of the cable jacket shown in FIG. 5;
FIG. 7 is a cross-sectional view through line VIIxe2x80x94VII in FIG. 5;
FIG. 8 is a cut-away perspective view of an electrical cable showing still another embodiment of the present invention;
FIG. 9 is a cross-sectional view through line IXxe2x80x94XI in FIG. 8;
FIG. 10 is a cross-sectional view through line Xxe2x80x94X of FIG. 8 of a repair boot embodying the present invention which may be used, for an example, on the cable shown in FIG. 8, or outer electric cable assemblies;
FIG. 11 is a cross-sectional perspective view of a roll of repair tape which may be used, for example, in or on an electric cable assembly;
FIG. 12 is a cross-sectional perspective view through line XIIxe2x80x94XII of FIG. 8 of an electrical conduit which may be used, for an example, to house, guide flame path, or give extra mechanical abrasive protection to original cable shown in FIG. 8,or inner electric cable assemblies;
FIG. 13 is a broken of perspective view of an electrical extension cord;
FIG. 14 is a broken of perspective view of an electrical power cord;
FIG. 15 is a cross-sectional perspective view of an electrical wire or cable;
FIG. 16 is a cross-sectional perspective view of an electrical wire or cable;
FIG. 17 is a cross-sectional perspective view of an electrical wire or cable;